Sure, things existed. mySQL is a great database, but so is Mongo and so is Clickhouse and so is Firebase, etc. Those alternatives all filled a gap MySQL couldn't, and now the bar for creating a new type of database is significantly higher because there's fewer gaps (schema-less, good for logs, good for fulltext search, realtime, etc).

JavaScript has been around for decades. But jQuery made it so much easier, and then React built on top of that even more. And jQuery wasn't the first DOM library, nor was React the first framework – but both were where it seemingly clicked between ideas, usability and whatever else made them successful.

(I will agree that Microsoft had a run of things where anyone who bought in to their ecosystem had a lot of things that worked well together.)

Exactly, the web as an app platform didn’t really take off until 2008. If you were a pure Microsoft shop from top to bottom, all you needed was an MSDN subscription provided by your employer.